Hey guys ,been reading all over as well as posting in some places.Most everyone on the site,who runs an automatic, prefers the 400 turbo trans.Why is this?I have always heard that a powerglide belongs in a race car,but with most of you building stroker and forced induction motors,it just seems like you are wasting power by running a heavy trans with heavy parts.I know that they are strong with the right parts and I even have one in the garage,that is pure factory.But I wonder if most of the cars I am reading about wouldn't be faster with a powerglide.Especially those making in excess of 600 Hp.I know when I had my 350 turbo built it cost me 6 bills minus the converter and it has a hardened sprag and drum,plus red clutches,racing steels and band and a host of other parts.The powerglide that will replace it,when I get done with it,is an ATI piece with 1.80 straight cuts,trans. brake,turbo spline input shaft ,modified the drum to take 7 Ford clutches,hint,hint.You get the idea. Powerglides like this one will handle 900+ hp. and more in a 3400 lb car.So ,whats the deal?Thank you ,Eric.
eric13617
well how i see it it depends on your setup, 456 rear end with a powerglide 3000 or so stall and a cam that only runs 5500 rpm in a quarter is gonna tach out! be fast on the street though. as to where a 400 you can get away with steeper gears. especially in a daily driver. i have a daily driven 468 with 373 gears and a th 350 that has only a 2500 hole shot and im suffering, 4000 rpm goin 70 on the freeway. i could use a 400! but with my 327, and 308 gears i loved my powerglide!! seemed like it would run from 60 to 100 in a few secs. but was a bit sluggish on the street with the 308s......................just one mans opinion.............
Powerglides are good for a car that weighs less than 2900 lbs. IMHO
The extra HP a TH400 requires is a moot point..its all about torque multiplication which ain't happening with a powerglide in a heavy car.
The extra HP a TH400 requires is a moot point..its all about torque multiplication which ain't happening with a powerglide in a heavy car.
Come on guys,some more please.
Gear ratios are as follows;Powerglide-1.76 or 1.82 1st gear and 1to1 high gear
350 turbo is 2.48,1.48,1.0.
400 turbo is 2.52,1.52,1.0
Now let me say,I don't know crap about 4 speeds but I do know in todays world that you can order any gear you want, to an extent,for any transmission.And although some might say that their car needs a 4.30 gear with a glide,or a 3.89 with a 400,if we are talking cruse Rpm.,it will be the same no matter what trans;unless its an overdrive or has a gearvender overdrive unit.If however we are talking seat of the pants "feel",I can understand how you would want a 400 or 4 speed.And as far as torque multiplication goes,if your tires won't handle it,you are wasting power.Now,real fast cars actually haze the tires off the line and most of the way down the track.But,if you "Blow the tires off",you are wasting power.And this is in direct relation to torque multiplication.
Gotta Go,"OUTLAW",called!
Gear ratios are as follows;Powerglide-1.76 or 1.82 1st gear and 1to1 high gear
350 turbo is 2.48,1.48,1.0.
400 turbo is 2.52,1.52,1.0
Now let me say,I don't know crap about 4 speeds but I do know in todays world that you can order any gear you want, to an extent,for any transmission.And although some might say that their car needs a 4.30 gear with a glide,or a 3.89 with a 400,if we are talking cruse Rpm.,it will be the same no matter what trans;unless its an overdrive or has a gearvender overdrive unit.If however we are talking seat of the pants "feel",I can understand how you would want a 400 or 4 speed.And as far as torque multiplication goes,if your tires won't handle it,you are wasting power.Now,real fast cars actually haze the tires off the line and most of the way down the track.But,if you "Blow the tires off",you are wasting power.And this is in direct relation to torque multiplication.
Gotta Go,"OUTLAW",called!
When you only have 4-5 seconds in your run there's not much time to think about shifting plus it takes between 1/4-1/2 sec to change a gear.
Those trannys are also tricked out with slipper clutches instead of converters so that they drag until you reach the desired rpms and with 4000-5000 hp thats all thats needed to over come the gear ratios.
Those trannys are also tricked out with slipper clutches instead of converters so that they drag until you reach the desired rpms and with 4000-5000 hp thats all thats needed to over come the gear ratios.
Eric, you have the TH350/TH400 ratios transposed.
The TH400 may be a little bit of an energy pig, but it is farm simple and durable for not much money. With few exceptions, most hot rod Chevelles are a bit of a compromise toward street driving. The more street friendly the differential gear, the better a TH400 works out for the average guy.
That said, I run a 200 4R (with a billet input shaft and forward drum) for nice and easy freeway driving. Locked up in 4th with 4.10:1 gears I am right at 2,500 rpm at 75 mph.
Thomas
The TH400 may be a little bit of an energy pig, but it is farm simple and durable for not much money. With few exceptions, most hot rod Chevelles are a bit of a compromise toward street driving. The more street friendly the differential gear, the better a TH400 works out for the average guy.
That said, I run a 200 4R (with a billet input shaft and forward drum) for nice and easy freeway driving. Locked up in 4th with 4.10:1 gears I am right at 2,500 rpm at 75 mph.
Thomas
Eric,food for thought...
My 3,945 lb. 70 SS454 ran a 12.99 with 2.56 gears and a TH400 with a 1.83 60 ft.
it would NOT have run that ET with a powerglide nor would it have done a 1.83 60 ft. with a powerglide
1.82 X 2.56=4.65 overall first gear
2.48 X 2.56=6.34 overall first gear
its all about torque multiplication and 60 ft. when it comes to a heavy car.
My 3,945 lb. 70 SS454 ran a 12.99 with 2.56 gears and a TH400 with a 1.83 60 ft.
it would NOT have run that ET with a powerglide nor would it have done a 1.83 60 ft. with a powerglide
1.82 X 2.56=4.65 overall first gear
2.48 X 2.56=6.34 overall first gear
its all about torque multiplication and 60 ft. when it comes to a heavy car.
Hey guys,Didn't mean to get you all upset.Just wanted to know what your thoughts were and why.I still believe that most high horse cars are better suited for a glide,especially if you make more than 500 ft.lb.at the flywheel.But,I understand that more of "you" have daily or at least weekend cruisers ,that happen to be Musclecars.This is why I see rear gears in the 2.73 to 3.73 ratio.And,I totaly agree that with a 265,283,302,305,307,327,
350,or even a 383 that a 350 or 400 turbo,200R,or another overdrive would be the best choice in an automatic transmission.
But,with any engine over 400 inches with any power to speek of,with the right combination of parts,and I mean from the carb to oil pan,torque converter to tire diameter,no matter what the weight,as long as it's not a tank,the car should respond better with a Powerglide.
This is my opinion and as it's said,"Opinions are like A-holes and everyone has one."
350,or even a 383 that a 350 or 400 turbo,200R,or another overdrive would be the best choice in an automatic transmission.
But,with any engine over 400 inches with any power to speek of,with the right combination of parts,and I mean from the carb to oil pan,torque converter to tire diameter,no matter what the weight,as long as it's not a tank,the car should respond better with a Powerglide.
This is my opinion and as it's said,"Opinions are like A-holes and everyone has one."
Actually, WEIGHT IS everything in what determines the trans you should use. ALL of my engines are over 400 cubes and ALL of my cars make power. (Remember, I own a hotrod shop) I don't mean to sound mean, but you are going to be sadly disappointed in your car when you find out that it only makes 400 or so HP and you stuck it in front a glide. For the record, my everyday driver has a 454, Th400, 4.11's and no overdrive. My wife's Camaro has a 454, Th400, 4.11's and no overdrive, My Nova has a 10:1 402, 4 speed and will have 3.73's because I want to drive it more!
....again, no overdrive. Even with torque and horsepower, ya' still gotta get it off the line.
....again, no overdrive. Even with torque and horsepower, ya' still gotta get it off the line.My dad has a 68 Camaro with a 400 sbc, a 4 speed Muncie with 1st gear ratio and a 3.55 rear.
A guy that he knows claimed his 69 Chevelle with 396, PG and 3.73's could take my dad's Camaro.
My dad has ridden in his car and said "it didn't get out of the hole very well"....hhhmmmm wonder why that is?
Could it be the 2.20 1st gear multiplied the torque better than the 1.76 1st gear? Not to mention I believe my dad's engine is stock out of a '70 pick up, in stock form for 70 the 400 made 260 hp/400 tq whereas the 396 was making 325/350/375 and 415 tq....
About the only time I think a PG would perform as well is if you had a real torquey engine before it, but then it wouldn't be an apples to apples comparison anymore.
There's a reason why you have 4 speed autos in todays newer cars and trucks, and that's because they're more efficient than their older siblings....otherwise we'd still be running powerslides.
A guy that he knows claimed his 69 Chevelle with 396, PG and 3.73's could take my dad's Camaro.
My dad has ridden in his car and said "it didn't get out of the hole very well"....hhhmmmm wonder why that is?
Could it be the 2.20 1st gear multiplied the torque better than the 1.76 1st gear? Not to mention I believe my dad's engine is stock out of a '70 pick up, in stock form for 70 the 400 made 260 hp/400 tq whereas the 396 was making 325/350/375 and 415 tq....
About the only time I think a PG would perform as well is if you had a real torquey engine before it, but then it wouldn't be an apples to apples comparison anymore.
There's a reason why you have 4 speed autos in todays newer cars and trucks, and that's because they're more efficient than their older siblings....otherwise we'd still be running powerslides.
I had a Powerglide and like I said before it was a POS. A total dog off the line and you were in 1st forever. I blew it up on the first time I hit the street with the new 350. When I changed to the 350 turbo, it was like night and day. The 400 turbo is a power pig and you can tell. I would only use it if you had a high horsepower/torque car. Otherwise the 350 is King. I have a 350 behind my 462 and a 400 behind my 327. The 400 will stay where it is and I will use the 350 in my big block car (Camino) to get the most power to the pavement. I love the 350 Turbo.
I'll see ya'll later. Mac
I'll see ya'll later. Mac
Just for the record -
The GM difference in flywheel vs rear wheel hp for a powerglide averaged about 19hp
The difference in the TH-400 was about 45hp
The difference in the Th-350 was about 30hp
The TH-400 is one tough tranny. I've got one in my '77 truck and i abuse it. Horribly. I "rebuilt" because i wanted to see how it worked as much as anything. I replaced the friction material and the bushings and winged a shift improver based on some stuff i read and the instructions from a kit from a 350. Alot of fun, but nothing really needed replacing except the kick-down solenoid because the insulation on the wire chipped off and it was touching the inside of the case. Friction material was only slightly worn in comparison with the new ones. The only thing that caused me grief was a worn TC neck that was allowing excessive drain back.
The GM difference in flywheel vs rear wheel hp for a powerglide averaged about 19hp
The difference in the TH-400 was about 45hp
The difference in the Th-350 was about 30hp
The TH-400 is one tough tranny. I've got one in my '77 truck and i abuse it. Horribly. I "rebuilt" because i wanted to see how it worked as much as anything. I replaced the friction material and the bushings and winged a shift improver based on some stuff i read and the instructions from a kit from a 350. Alot of fun, but nothing really needed replacing except the kick-down solenoid because the insulation on the wire chipped off and it was touching the inside of the case. Friction material was only slightly worn in comparison with the new ones. The only thing that caused me grief was a worn TC neck that was allowing excessive drain back.
It is interesting when people can get close to understanding, but then maybe interpret their observations in a different direction.
At the dragstrip it often happens that some people are complaining about lack of traction, while others are setting peersonal bests in e.t.'s. Why is that? Its not just that one car has more power than another, or has slicks, etc. - its in the total combo. And so it is that a wide range of similar cars will have better results with one kind of transmission or another.
The gear ratios in your transmission, your differential, and the radius of your tires are nothing more than a lever. The gear ratios are a multiplier, the tire radius is a divisor.
For every total car drivetrain, tire, suspension, and weight combo there is a maximum amount of "lever" that combo can handle off the line. If you apply too much lever it wastes the power and leads to undesireable wheel spin, with too little lever it bogs and is needlessly slow off the line. Get it just right and it is sweet and fun to launch.
In simple terms one of the reasons why many drag cars do well with a Powerglide is that the rest of the combo has been well optimised and the Powerglide provides all the lever need for a great launch.
In an unoptimised car which might lack one or more of the following: horsepower, differential gear ratio, torque converter stall - then the greater lever of a three or four speed automatic will be preferable over a Powerglide.
Conversly, if an unoptimised car, even a heavy one, has more power than it has suspension - then it may prefer the shorter lever of the Powerglide to help it get off the line without wasting power through wheelspin.
I'm not at all surprised that a well set up 1,160 horsepower car is running a Powerglide. Generally the higher the horsepower the shorter the lever that is needed or wanted for launching.
Thomas
At the dragstrip it often happens that some people are complaining about lack of traction, while others are setting peersonal bests in e.t.'s. Why is that? Its not just that one car has more power than another, or has slicks, etc. - its in the total combo. And so it is that a wide range of similar cars will have better results with one kind of transmission or another.
The gear ratios in your transmission, your differential, and the radius of your tires are nothing more than a lever. The gear ratios are a multiplier, the tire radius is a divisor.
For every total car drivetrain, tire, suspension, and weight combo there is a maximum amount of "lever" that combo can handle off the line. If you apply too much lever it wastes the power and leads to undesireable wheel spin, with too little lever it bogs and is needlessly slow off the line. Get it just right and it is sweet and fun to launch.
In simple terms one of the reasons why many drag cars do well with a Powerglide is that the rest of the combo has been well optimised and the Powerglide provides all the lever need for a great launch.
In an unoptimised car which might lack one or more of the following: horsepower, differential gear ratio, torque converter stall - then the greater lever of a three or four speed automatic will be preferable over a Powerglide.
Conversly, if an unoptimised car, even a heavy one, has more power than it has suspension - then it may prefer the shorter lever of the Powerglide to help it get off the line without wasting power through wheelspin.
I'm not at all surprised that a well set up 1,160 horsepower car is running a Powerglide. Generally the higher the horsepower the shorter the lever that is needed or wanted for launching.
Thomas
Thanks guys,I think I'll quit now,before someone else says something else about my car that they can't back.Just remember this,my Small block was rated at 370 hp.factory.15 years ago ,it made 413 hp.with the factory double humps and a hydraulic cam,dynoed at Race Engine Design,in Chatanooga,TN.
Since then its recieved,CNC'd Alum. heads ,Solid Roller Cam,RPM Air-Gap,Barry Grant carb and the list goes on.I think the days of 400Hp.or so are gone.Thank you all for the input and stay safe.
Since then its recieved,CNC'd Alum. heads ,Solid Roller Cam,RPM Air-Gap,Barry Grant carb and the list goes on.I think the days of 400Hp.or so are gone.Thank you all for the input and stay safe.
I originally saw them on a poster in a GM performance shop. It looks like most of the stuff on the internet is based on a percentage, which makes more sense to me. GM said "average" but it must have been behind engines that were turning the same HP.
Here's a link that says the same thing i do - but it looks like this guy is doing it from memory too :sad:
http://www.442.com/oldsfaq/oftrn.htm
Here's a link that says the same thing i do - but it looks like this guy is doing it from memory too :sad:
http://www.442.com/oldsfaq/oftrn.htm
i had a glide w/3000 stall, 4:56 gears in my car...it was a 13.0 car... i raced a friend and we were bumper to bumper, i put in a th350, same converter... boy that first gear sure felt good in the seat of the pants, but guess what we were still bumper to bumper! ...my car is about 3700#, with a low torque, high rev 350 (gm off road gen1 cam, so i spun it to 7200). From my experience the 3 spd gave more 'feel' of acceleration, but didnt accomplish anything in the 1/4 mi over the glide.
Has anyone else heard that a th350 will hold up behind a BBC better than a high rev SBC (under 500hp or so), at least i've heard/seen this to be true. Apparently the high revs were causing too much pressure in the tranny and oil was pushing past the clutches and burning out the reverse clutch...this was on high reving SBC's.
ak
Has anyone done the swap from a 3sp to a glide without changing other factors and tested the results at the track??
Has anyone else heard that a th350 will hold up behind a BBC better than a high rev SBC (under 500hp or so), at least i've heard/seen this to be true. Apparently the high revs were causing too much pressure in the tranny and oil was pushing past the clutches and burning out the reverse clutch...this was on high reving SBC's.
ak
Has anyone done the swap from a 3sp to a glide without changing other factors and tested the results at the track??
The reason everyone likes the 400, even to use with a small block is because it will take almost any kind of power you throw at it. It is a very tough tranny.
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